[wting]

In Haskell:

Variables? What state? Everything is puuuuuuuuure.

In Python:

Everything is an object (numbers, true/false values, strings, etc), some are mutable and some are not. Variables are temporary labels on objects (think of them as hard links).

In Rust/C++:

There are various types of boxes / smart pointers (shared, unique, heap, etc), and unsafe / raw pointers should be avoided when possible.

In C:

Not every variable has a data type, e.g. void or function pointers.

[_kst_]

"Not every variable has a data type, e.g. void or function pointers."

A void pointer has type "void* "; a function pointer also has some appropriate type.

Not every object has a type (e.g., a chunk of memory allocated by `malloc()`), but if "variable" means "object created by a declaration", then yes, every object has a type.